In hybrid vehicles with a stop/start device, the internal combustion engine is switched off automatically if no driving force is required, for example when the vehicle is stopped at a traffic light. As soon as driving force is required again, that is to say for example when the traffic light switches to “green” and the driver activates the accelerator pedal, the vehicle is restarted by means of the electric motor. Various strategies have been developed for controlling the automatic switching off of the internal combustion engine in hybrid vehicles with a stop/start device.
EP 1 469 195 A1 discloses a method in which the internal combustion engine shuts down automatically as soon as the operating conditions which are provided for this are met for a predefined time. In this method, in a situation in which all the conditions for the switching off are met, the driver can prevent the automatic switching off of the internal combustion engine within the predefined time by, for example, activating within this time a button, depressing the brake pedal to a greater degree or issuing a voice command.
EP 1 534 554 B1 discloses a method for controlling a drive train which permits individual adaptation of the drive train management system by the driver and to the driver, for which purpose the drive train management system carries out a learning function in which it changes associated parameters or state data of the drive train to adapt them to the driving behavior.
U.S. Pat. No. 6,941,218 B2 discloses a stop/start device for a locomotive and a method for controlling this device, wherein there is provision for the stop/start device to be deactivated in reaction to a deactivation command.
While hybrid vehicles with a stop/start device are operating, there may be the problem that switching off of the internal combustion engine or restarting it in the respective current situation does not correspond to the driver's wishes. For example, the situation may occur in which the driver stops temporarily at an intersection due to the traffic and the stop/start device switches off the internal combustion engine at just that time at which the driver would like to drive off again owing to the changed traffic conditions. Furthermore, in some cases the driver carries out parking maneuvers during which it is undesirable for the internal combustion engine to be switched off and restarted. whenever the brake pedal or accelerator pedal is activated.